Thank you for choosing Aerospace-Aviation360 for Part Number 4770182 described as Tester, Battery Ni-Cad. Applies Calibrated Load To Battery To Indicate 23 1/2 Volt Charge Condition. by Mcdonnell Douglas. This is an ASAP Semiconductor owned and operated website. We are a leading supplier of aircraft tooling parts. You have 24/7 x 365 access to our diverse product database with the fastest lead times in the industry.